ECOM broadcasting

[Gummi Ben]

Hello, I just received a question from a customer of mine that has a few PLC's with ECOM modules that are communicating with a KEPDirect OPC server.  The question was why the ECOM modules were sending a broadcast packages instead of just messages directly to the OPC server.  Is there some way to configure this in ECOM unit or perhaps in the OPC server.

Best regards,

Gudmundur Ben

[franji1]

I am not famililar with the KepDirect software (it is not a Host product), but in this type of setup, the KepDirect Server is actually the Master to the ECOM Slave (although it is the Server to your PC applications).  The "Communications Link" for the KepDirect Server for each of the ECOM modules need to be configured for TCP/IP (not IPX) protocol, using a valid IP Address as the "address", not the Module ID or the "Name" or the Ethernet/MAC Address.  The KepDirect "Link" name should not need to be changed, just its configuration, so any OPC clients referring to that name should not need to change either.

Someone who is famililar with KepDirect software may be able to explain better how to do this.  You may also try posting on ADC's forum.

Note that you may need to configure your ECOM's IP addresses (this may have never been done).  If you need help with that, start with the NetEdit3 utility.  If you don't have it, it's available for free on our main site.

[Greg]

franji1, I'm really puzzled by the ECOM sending broadcasts if it is the slave. It should just respond in like manner that its being talked to by KepDirect software, shouldn't it? However, if the ECOM is the master and is sending on its own initiative to the KepDirect software, then I could understand why it is broadcasting.

[BobO]

About the only time it should initiate a broadcast is when doing an RX/WX without a peer entry or some kind of RBE where there is no specific target. Even when responding to broadcasts for RX/WX slave side or for configuration, it should respond to the address it got the broadcast from. I suspect there is more to the story here. Might also be prudent to get Don involved.

[Greg]

Gummi Ben, are there any RX/WX (or ECRX/ECWX) instructions in your PLC's ladder logic that are using your ECOM?

[Gummi Ben]

Hi all and thanks for all your replies.  Yes Greg, some of the PLC's are using some RX instructions but I'm not sure if there are any WX instructions.  Are the ECOM units using broadcast if an RX instruction is used with the unit ID as an address ?

[BobO]

Are the ECOM units using broadcast if an RX instruction is used with the unit ID as an address ?

Yes. You can prevent that by creating peer table entries and specifying IP addresses for each target node.

[Greg]

Gummi Ben, this also most likely means that the broadcasts you are seeing are not because of the KepDirect OPC Server, but rather from the RX instructions.